1. Technical Field
The present invention generally relates to an image capturing device that obtains spectral information from an object, and an image capturing system provided with the image capturing device.
2. Description of the Related Art
The spectral reflectance or the state of the object may be obtained through evaluating the spectral information of the object, which may be measured using a spectrometer such as a prism, grating, or liquid crystal tunable filter. While a spectrum of a point or a line of the object can be measured at once using the spectrometer, a surface of the object is usually measured by scanning the object using a linear spectrometer. Especially when the object is a moving object, such as a cell, measuring the spectrum of the object surface with improved accuracy has been difficult.
Japanese Patent Application Publication No. JP2001-99710-A discloses a method of estimating a spectrum of an object from a multi-band image, which is generated based on a plurality of original images each being captured using a wavelength variable filter. More specifically, the wavelength variable filter is used to change a wavelength range corresponding to each channel to obtain a plurality of original images of the object. The spectrum of the object is estimated using the multi-band image generated based on the plurality of original images. Since switching of the wavelength range is required, a spectral image of the plurality of channels cannot be measured at once. Assuming that the number of channels is equal to or greater than 10, the channel of the wavelength variable filter needs to be changed for 10 times or more to obtain a band image for each channel, thus requiring processing time. Especially when the object is a moving object, the accuracy in measuring the spectrum may greatly suffer.